1. Field
The following description relates to a communication technology of an access point and terminals for an uplink multi-user multiple-input multiple-output (MU-MIMO) channel access.
2. Description of Related Art
As the number of users and the various applications such as voice, video streaming, and the like continue to increase in a short range communication network, throughput in the network must be improved. To enhance throughput, a scheme of increasing a usage bandwidth of a channel may be used. However, a limited frequency resource may hinder the usage bandwidth of a channel.
An access point may simultaneously transmit signals to multiple terminals during down-link communication, for example, using a multi-user multiple-input multiple-output (MU-MIMO) technology. In this example, if a relatively accurate time synchronization is maintained, the access point may transmit frames to multiple terminals.
However, during up-link communication, multiple terminals located at different positions may independently transmit frames to the access point. Accordingly, it may be difficult for the access point to receive each of the respective frames transmitted by multiple terminals with relatively accurate time synchronization.
Accordingly, there is a desire for a communication method that is capable of enhancing throughput while multiple terminals transmit uplink data with relatively accurate time synchronization in a random access communication environment in which multiple terminals independently access a channel, such as a wireless local area network (LAN) system.